does the SP4 not stop charging when its fully charged by dock? I read somewhere that surface show "plugged in" sign in battery options when it is fully charged. But that doesn't happen with my SP4. But I don't have the dock yet, that may be due to the connected dock?

<<...does the SP4 not stop charging when its fully charged by dock?..>>

...The issue isn't just constant charging. It's also keeping the battery at or near 100% change for lengthy periods of time even if it's only periodically charging. I don't use the Surface dock (so I'll let someone else answer your specific questions about that) but I have to use a dock for my work laptop, which spends probably 99% of its time docked. On the occasions when I travel, the battery operating life is only about an hour... or less.

So I believe that docking can adversely impact your battery life if you leave your computer docked for lengthy periods of time...

I'm not so sure. At least on my Surface 3, I haven't noticed much difference in overall battery wear both ways. But I don't take any special precautions to reduce battery wear. If fact, quite the contrary.

You can mitigate any possible effect by using your SP4 on only on battery when you take it home or other places. I don't know there is really a lasting effect or not from being tied to a charger these days, but in the pre-Li days (or even early Li days) if you never took it off the charger you'd go to use it and it would die in a few hours, if not quicker.

I wanted to update my surface dock FW. Downloaded the current version of surface dock updater. The update seemed to go well, but every time I re-run the updater, it starts up with the update screen again?